Biostatistics and Bioinformatics Staff, Office of Analytics and Outreach, Center for Food Safety and Applied Nutrition, US Food and Drug Administration, College Park, MD, United States of America.
Division Of Plant Products & Beverages, Office of Food Safety, Center for Food Safety and Applied Nutrition; US Food and Drug Administration, College Park, MD, United States of America.
PLoS One. 2022 Sep 1;17(9):e0268470. doi: 10.1371/journal.pone.0268470. eCollection 2022.
Food production facilities are often routinely tested over time for the presence of foodborne pathogens (e.g., Listeria monocytogenes or Salmonella enterica subsp. enterica). Strains detected in a single sampling event can be classified as transient; positive findings of the same strain across multiple sampling events can be classified as resident pathogens. We analyzed whole-genome sequence (WGS) data from 4,758 isolates (L. monocytogenes = 3,685; Salmonella = 1,073) from environmental samples taken by FDA from 536 U.S. facilities. Our primary objective was to determine the frequency of transient or resident pathogens within food production facilities. Strains were defined as isolates from the same facility that are less than 50 SNP (single-nucleotide polymorphisms) different from one another. Resident pathogens were defined as strains that had more than one isolate collected >59 days apart and from the same facility. We found 1,076 strains (median = 1 and maximum = 21 strains per facility); 180 were resident pathogens, 659 were transient, and 237 came from facilities that had only been sampled once. As a result, 21% of strains (180/ 839) from facilities with positive findings and that were sampled multiple times were found to be resident pathogens; nearly 1 in 4 (23%) of L. monocytogenes strains were found to be resident pathogens compared to 1 in 6 (16%) of Salmonella strains. Our results emphasize the critical importance of preventing the colonization of food production environments by foodborne pathogens, since when colonization does occur, there is an appreciable chance it will become a resident pathogen that presents an ongoing potential to contaminate product.
食品生产设施通常会定期进行常规检测，以确定是否存在食源性病原体（例如单核细胞增生李斯特菌或肠炎沙门氏菌亚种肠炎沙门氏菌）。在单次采样事件中检测到的菌株可被归类为暂存菌；在多次采样事件中发现的同一菌株可被归类为常驻病原体。我们分析了来自美国食品药品监督管理局从 536 家美国工厂采集的环境样本的 4758 株分离株（单核细胞增生李斯特菌=3685 株；肠炎沙门氏菌=1073 株）的全基因组序列（WGS）数据。我们的主要目标是确定食品生产设施中暂存菌或常驻病原体的频率。菌株被定义为来自同一设施的分离株，彼此之间相差不到 50 个 SNP（单核苷酸多态性）。常驻病原体被定义为在相隔超过 59 天且来自同一设施的多个样本中收集到的菌株。我们发现了 1076 株（中位数为 1，每设施最大为 21 株）；180 株为常驻病原体，659 株为暂存菌，237 株来自仅采样一次的设施。因此，在多次采样且发现阳性结果的设施中，有 21%（180/839）的菌株被发现为常驻病原体；近 1/4（23%）的单核细胞增生李斯特菌菌株被发现为常驻病原体，而沙门氏菌菌株为 1/6（16%）。我们的研究结果强调了防止食源性病原体在食品生产环境中定植的重要性，因为当定植发生时，存在相当大的机会成为常驻病原体，持续存在污染产品的潜在风险。
